| With the rapid growth of the world economy, global demand for electricity is incontinuous growth as well. However, fossil fuel exhaustion and environmental pollution isserious increasing, thus promoting the development and utilization of renewable energygeneration technologies such as wind power. Wind energy is currently the most potentialrenewable energy source for large-scale commercial development and the networkingoperation of wind power is an effective way to realize the large-scale development andutilization of wind power. However, wind power has the characteristics of fluctuant,stochastic and variable, the grid interconnection of large-scale wind power has broughtgreat impact to the safe and stable operation of power grid. Therefore, how to take effectivemeasures to smooth output fluctuations of wind farms to ensure the operational security andreliability of power grid, has the positive significance to the grid interconnection oflarge-scale wind power.Energy storage technology can be used in renewable energy systems to provide theenergy buffer and the reserve balance effect, thus drawing more and more attention inrecent years. Using the energy storage device in the wind power generation system, caneffectively reduce its power fluctuations, mitigate its negative influence to power system,ensure the operational security and reliability of power system and improve the capacity ofwind power integrated into the grid. In a variety of energy storage technologies, the flowbattery and super capacitor have lots of advantages such as quick power response, highstorage efficiency, long lifespan as new energy storage technologies, which are verysuitable for use in wind power generation system. In addition, the cost of energy storagesystem is quite expensive at present. It of great theoretical and practical significance toselect proper capacity of energy storage device to make the system meet the reliability andeconomy requirements at the same time for the extension and application of energy storage.Therefore, this paper will focus on optimal configuration of capacity of flow battery energystorage and super capacitor energy storage using in wind power generation system.This paper firstly analyzed the fluctuation characteristic of wind power output, thenthe evaluation index of optimal configuration of energy storage capacity was giving, whichlaid the foundation for the configuration of energy storage capacity to smooth wind powerfluctuation. Secondly, this paper established mathematical model of optimal allocation ofenergy storage capacity, which aimed at reducing the wind power fluctuation by flowbattery. A numerical example was given for the model by using chaotic particle swarm optimization algorithm, and got an optimal allocation result of energy storage capacity withideal smooth effect and certain economy. Finally, aiming at flow battery-ultracapacitorhybrid energy storage system, this paper designed a coordinate control strategy based onlow-pass filter principle. The capacity of the hybrid energy storage system was determinedby making the flow battery and super capacitor compensate the wind power outputfluctuation classification according to time behavior. The numerical example gave theoptimal configuration result of hybrid energy storage capacity, and analyzed the technicaland economical advantages of hybrid energy storage compared to the single way of energystorage. |
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